Electric-arc lamp.



" N 669,055- hunted nu. 2s, 190|.

vM. H. BAKER.

ELECTRIC ARC LAMP.

. (Anuman md am. u, 1999.)

(Ilo Ioddl.) 2 Shun-Shoot l.

Patented rp. 2s, lsol.

n. H. Immun.v

ELECTRIC ABE LAUF.

(Applicltion'lod Sept. 5, 1899.)

2 Shank-Shea! 2.

(llo Iodol.)

Tui noemt m eo.. mo'ro'urnu. mamme-Yon, o. c

UNITED STATES PATENT OFFICE.

MALCOLM H. BAKER, OF NEW YORK, N. Y., ASSIGNOR TO THE MANHATTAN GENERALCONSTRUCTION COMPANY, OF NEVV YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 669,055, dated February26, 1901.

Application filed September 5, 1899. Serial No. 729,440. (No modell Tof/,Z 'lull/0117. may concern:

Beit known that I, MALCOLM H. BAKER, a citizen of the United States, anda resident of New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Central- CoreArc-Lamps, of which the following is a specification.

The subject of the present invention is an 1o arc-lamp capable of beingused upon either series or multiple circuits and of being operated byeither direct or alternating currents. It has been impossible heretoforeto construct a commercial arc-lamp for use on alternatingt 5 currentcircuits in which the solenoid-magnet and armature were concentric withthe carbon and the carbon tube or rod of the lamp. It has been usual toemploy a series winding on one or more magnet-spools and to arrange zothese at one side of the carbon tube or rod, whereby there has beenconsiderable loss. In other words, no one has heretofore succeeded inconstructing an alternating-current arc-lampof the concentrictype--thatis to say, a lamp in which the solenoid and thecarbon-carrying rod or tube have a common center. I have constructedsuch a lamp and I [ind that it is capable of perfectly successful use onaltemating-current circuits as well 3o as circuits operated by thedirect current. When used upon'alternating-current circuits, the lamp ist'ree from noise or vibration, the workingv parts being controlled bythe opposing action ot a weight acting to draw the arc 55 and aconcentric solenoid in a shunt to the arc. There are no series windingsemployed in the lamp mechanism. For this reason and because, as stated,the working parts are controlled entirely by gravity and by a concentricmagnet arranged as a shunt across the arc it follows that the operationot' the lamp is virtually independent of the amount of current liowingthrough the main circuit, which includes the carbons. For

this reason the lamp when used upon multiple alternating-currentcircuits may carry a small regulating-coil, as described farther on,which will maintain the current constant at any desired value, and thuscause the lamp 5o to be independent of the voltage or the variations, asabove described, or the lamp may carry a lixed reactance-coil, and theadj ustment for varying voltages may be made by changing the numbei1 ofturns in use on the shunt-coil until the desired amount of current flowsin the main circuit. The adjustment of the arc-voltage is made entirelyby altering' the position of the counterweight, and

after once being fixed it need not bealtered. Owing to the structure ofthe lamp and the 6o fact that the arc is drawn slowly by the action ofthe counterweight the starting of the lamp is always accomplishedWithout any shock or jar or strain of any kind, whereby the life wear ofthe moving parts is considerably increased.

The main structural features ot' the lamp remain unchanged under all theconditions enumerated, except that the size of wire employed in thesolenoid-magnet winding is va- 7o ried and that a reactance-coil,resistancecoil, or a cut-out is introduced in the lampbody according asthe lamp is used upon multiple or series alternating-current or multipleor series direct-.current circuits.

In adapting my lamp to the above-designated uses I have developedcertain novel structural arrangements and devices which constituteimprovements in a lamp of this kind,'and it is upon these structuralarrange- 8o ments and devices that I rely mostly for producing theresults at which I have aimed.

One ofthe peculiarities of the arrangements referred to is that ofnormally withholding the upper carbon from contact with the lowerthrough the act-ion ot' a counterbalancingweight and of establishing thearc by first drawing down the upper carbon by means of the concentricmagnet, whereupon the counterweight draws up the carbon as soon as the9o current passes through the main lamp-circuit, including the carbons,and thus lowers the voltage across the concentric-magnet tern minals. Tomake this arrangement effective,

I rigidly attach to the carbon-holding tube a sleeve consisting ofseveral layers of thin iron, which constitutes the core of theconcentric magnet and is drawn down by the latter at starting, wherebycontact is established between the carbons. Thereupon the weight too orconnterbalance assumes control of the carbon-carrying tube and withdrawsthe set tube and carbons until a balance is established between thedownward pull ot' the solenoid and the upward pull of the weight.

By the employment of the lamp structure above described I do away withall springs and with practically all vibrations of the lamp mechanism.Inasmuch as the arc-voltage is maintained constant the life of thecarbons is practically constant.

In order that the details of my invention may be fully understood, Ihave illustrated the same in the accompanying drawings, in which- Figure1 is a side elevation of one of my improved arc-lam ps. Fig. 2 is asimilar view of the carbon-carrying tube detached, the lower part of thesaid tube being shown in section. Fig. 3 is a central vertical sectionofthe upper portion ofthe lamp-frame, showing the lamp-clutch in place.Fig. 4 is a detail view of the detachable clutch which I employ inconnection with my lamp. Fig. 5 is a perspective of the lower part ofthe frame for holding` the lower carbon. Fig. G is a diagram of thecircuits of my lamp as adapted for series lighting, and Fig. 7 is adiagram of the circuits ot my lamp as adapted for multiple work.

In the drawings, land 2 are, respectively, the binding-posts for theincoming and outgoing circuits of my arc-lamp.

At 3 I show a third binding-post, which is capable of being electricallyjoined to the binding-post 1 in the usual manner for cutting the lampinto and out ot' the main circuit by means ot aswitch-arm el, operatedby a handle In a series lamp the main circuit passes from thebinding-post 1, along the wire o', carbon-carrying tube 7, upper andlower carbons S and 9, and the wire 10 to the bindingpost 2. Ashnntcircuit extends across from the wire G to the wire 10 through aconcentric solenoid-coil 11. The said solenoid 11 is supported on theoutside of a tube 12, which surrounds the carbon-carrying tube 7. Thesaid tube 12 is a split tube of brass secured at one end to a split diskor plate 13, of similar material, and at the other to a split laminatedhead 14, of iron, the said disk 13 and head 14 constituting the ends orheads between which the solenoidcoil is wound. rPhe solenoid thusconstituted is set into a trame 15, of iron, consisting of the heads 1Gand 17, supported and held in a fixed position with relation to eachother by means of arms or posts 1S and lil. These arms or posts maybeformed in one piece with the heads 1o' and 17 or they may be joinedthereto by any suitable means. It should be noted that iron washers S1are placed on the lower end of the solenoid, so that the solenoid-core,these heads, the iron lamp-body, and the upper laminated iron head ofthe solenoid constitute very nearly a closed magnetic circuit. 'The head16 is provided at the top with a screw-threaded boss 60 for receivingthe lower screw-threaded end of a metallic tube 20, which when securedin place within the said boss constitutes, practically, au extension ofthe tube 12, surrounding the carbon-carrying tube. On the top of thetube 2O a cross-arm 2l, which carries the bindingposts l, 2, and 3, issecured by any suitable means. I show the said cross-arm as being formedintoa cap at its center and fitted over the upper end of the tube 2O andas being held in place by set-screws 22 Any other suitable device forsecuring the crosspiece to the tube may be employed. In the upper end ofthe tube 2O is firmly secured a plate or disk 23, closing` the said endand carrying a screw-threaded rod 2i, which receives` ascreweye 25 forsuspending the entire lamp structure.

The carbon-carrying tube 7 is supported within the tubes 12 and 20,being so suspended in the said tubes as to have free longitudinalmovement therein when the conditionsare suitable. A separate view ofthesaid carbon-carrying tube appears in Fig. 2. It will be seen that theupper end of the said structure is formed into a pairot arms 2G 27,between which the plunger 7l ot' a piston 28 is swiveled. The saidpiston acts, as is well understood, as a dash-pot device, in connectionwith the closed upper end of the tube 20, to prevent too-suddenmovements of the carbon-carryingt ubc. Between the opposite ends of thearms 26 27 is pivoted a tongue 29, which is itself formed into a lyokeat its 'free end and has pivoted toit a link 30. The said link 30extends outward through an opening in the tube 2O and is pivotedcentrally to lugs 3l 3l on the outside thereof. On the outer end of thelink 3() a screw-thread is formed and by means of this formation ascrewthreaded weight or counterbalanee is capable of adjustment on thesaid link. Thus the weight 32 acts to hold the carbon-carrying tube 7 ina raised position within the tubes 12 and 2O unless the power of thesaid weight is resisted by some other iorce. 'lhis forceis provided bythe solenoid 11, and in order to give eiiect to this forceI providearing or sleeve 33, otiron, surrounding the carboncarrying tube 7 andnormally located above the center of the solen l1, so that when the saidsolenoid is energized by the passage of' an electric current themagnetic pull will tend to draw the tube 7 downward against the force ofthe weight Accordingly when the lamp is inaction the posit-ion ot' thecarbon-carrying tube,aud consequentlyof the upper carbon, is determinedby the balance between the power of the weight. and the magnetic pull ofthe solenoid 11.

The connections at the upper end of the earbon-carryiupr tube 7, asbetween the said tube and the dash-pot piston and also as between thesaid tube and the external weight IOO IIO

32, are such as t-o give great freedom and flexibility to thereciprocating movements of the said tube. The effect of the weight 32aan be varied by adjusting the position of the said weight upon the link30. This capacity of my lamps for quick and easy adjustment in respectto current or arc voltage without removing the case from the lamp willbe found of advantage in the oase where it is desirable that a givenlamp or lamps should supply more light than others owing to the positionwhich the said lamp or lamps occupy.

On the lower end of the carbon-tube 7 is supported a ring 34, of anysuitable metal, and on the bottom of the said ring is formed an angulararm 35, constituting a bayonet connection for detachably supportingaclutch The said clutch is illustrated in detail in Fig. 4. The centralportion of the clutch is in the form of a ring adapted to surround thecarbon, with just enough intervening space so that the ring will notbind upon the said carbon when the clutch and the carbon are in planesat right angles to each other. When, however, the clutch is tilted withrelation to the carbon, it binds upon the latter and either holds it ina fixedr position or in case of a movement of the clutch carries thecarbon with it. It will be seen that the clutch is pro- 'Vided withprojecting arms on opposite sides of the central ring and that one ofthe said arms is adapted to enter the opening formed by the bending ofthe depending arm 35, while the other arm of the clutch is adapted torest upon a ledge formed by a bent arm 37, attached to the rigid orfixed part of the lamp. The said bent arm 37 is secured to but insulatedfrom an arm 38, depending from a metallic ring 39 on the lower end ofthe upper lamp-frame. The said ring is secured by screws toascrew-threaded T-shaped piece of metal 40, which in turn is secured byscrewbolts to a disk 41, of iron, constituting the lower end of a frame42. The last-named frame is secured by screw-bolts to the head 17, asshown, and the described parts unite to forni the lower end of the mainlamp structure. Between the disk 4l and the T-shaped piece 40 is a disk43, of metal, and a plate 44, of insulating material, is also insertedbetween the said parts.

The circuit of the lamp being closed, current passes through thesolenoid 11, draws down the carbon-carrying tube, and establishes themain circuit by bringing the carbons into contact. Current is thusdiverted from the solenoid-circuit, and the power of the solenoid isthereby weakened. Accordingly the weight 32 again lifts the uppercarbon', thereby establishing the arc. In the process of pulling downthe carbon-carrying tube the latter carries the clutch 3G into ahorizontal position, after which there is no resistance to the slidingof the carbon by gravity within the clutch until contact is made, asdescribed. On the surrender of the carbon-carrying apparatus into thepower of the weight 32 the bent arm 35 lifts one end of the clutch andcauses the latter to bind upon the carbon and raise it. 'lhus theclutch, although a separate and detachable part of the apparatus, ispositive in its action upon the carbon when the latter is moved forestablishing the arc. At other times, except when it has been carried`to a position at right angles to the carbon, it assists gravity inmoving the carbon'downward against the force of the weight 32.

The described construction furnishes an excellent counterbalance for themoving parts of an arc-lamp, relieving all shock, strain, or jar, and iscalculated to maintain the arc at a uniform length under all conditionsof the circuit.'

Wfhen it becomes necessary to trim the lamp, the trimmer i needs only tolift the clutch out of the bayonet-joint and slip it off with thecarbon, replacing both the clutch and the new carbon by reversing theprocess.

It should be stated that the upper carbon is secured within a split tube80, forming part of the usual carbon-rod, and that the latter, as shownin Fig. 2, is held in position within the carbon-carrying tube in theusual manner by means of spring-pressed bearings impinging againsttheinside of the said tube.

The part 50 represents the frame which carries the lower carbon. Thisframe forms no part of my present invention and is simply illustrated inorder to show a complete lamp.`

In Fig. 7 I have illustrated the arrangement of circuits for a serieslamp and in Fig. 8 the arrangement of circuitsfor a multiple-arc lamp.In the last-named lamp I employ a reactance-coil or a resistance 57, andI place it in the lamp-circuit, as shown, before leading off thesolenoid-circuit. In a series lamp constructed in accordance withmyinvention the binding-posts 2 and 3 are permanently connected by aWire 72, and when the lamp is in operation the switch-lamp 4 isdisconnected from the binding-post 2. tion of cutting out the lampconsists in moving the said switch-arm into'connection with the saidbinding-post. On the other hand, in a lamp adapted for use onmultiple-arc circuits'the binding-posts 2 and 3 do not have anyconnection except through the various lamp-circuits. The inleadingWireor main is connected to the binding-post l, and the lamp-wire 6 isjoined to the binding-post 2, so that in order to put the lamp intooperation it is necessary to move the switch-arm 4, so as to makeelectrical connection between the bindingposts I and 2. The lamp isswitched out ot the circuit by moving the said switch-arm away from thesaid bindingpost. i

I claim as my invention- I. In an arc-lamp, a carbon-carrier, and a tubesurrounding the same, a weight or counterbalance for the said carrierexternal to the said tube, and a'pivoted arm or link joining The opera-IOO IIO

the Said Weight und carbon-Carrier, the said weight or oountelbzila-noebeing;` adjustable on the said arm or link.

2. In an aro-lamp, a carbon-carrier and a. tube surrounding the same, aweight. 01' counterlmlance for the Said carrier external to the saidtube, and a pivoted arm or link joining the said Weight undcarbon-carrier.

Signed it New York, in the county of New York and State of New York,this 7th day of 1o August, A. D. 1899.

MALCOLM H. BAKER.

Witnesses:

WM. H. CAPEL, G. H. STOCKBRIDGE.

